This invention relates generally to devices for stereoscopic viewing and, more particularly, to a stereoscopic viewing apparatus and method for viewing two side-by-side related images, and to a stereoscopic recording useful therewith.
Stereoscopic viewing apparatus are used by a viewer to view two related two-dimensional images displayed on a suitable screen and thereby realize a three-dimensional effect. The related images depict the same scene, but as viewed from the perspectives of two locations spaced horizontally a distance approximating the distance between the centers of a typical viewer's eyes. The apparatus provides a three-dimensional effect by causing the viewer's left and right eyes to view the left and right displayed images, respectively. The perceived three-dimensional image has the two-dimensional proportions of the individual two-dimensional images being displayed.
One common type of stereoscopic viewing apparatus is used to view a motion picture of two related images that are projected onto a movie screen such that they overlap. In one version, the light defining the two images is polarized 90 degrees with respect to each other, and the movie screen is adapted to maintain the polarization. To separate the overlapping polarized images, the stereoscopic viewing apparatus includes appropriate polarized filters placed before the viewer's eyes. This polarization technique cannot be used with conventional television receivers, because, unlike movie screens, conventional television screens cannot display the requisite polarized images.
In another version of this common type of stereoscopic viewing apparatus, the two projected images are displayed in different colors, and the viewing apparatus separates the overlapping images using appropriately-colored filters placed before the viewer's eyes. A significant drawback to this version is that it cannot display images that are multi-colored, regardless of the type of display used.
Another example of a prior type of stereoscopic viewing apparatus views a motion picture of two related images that are displayed on a movie screen side-by-side, rather than overlapping. The device transmits the left and right images to the left and right eyes, respectively, without the use of filters. The images could conceivably be adapted for side-by-side display on the screen of a conventional television receiver. However, for the two related images and thus the three-dimensional image to have the same two-dimensional proportions (i.e., aspect ratio) as the conventional television image, the related images cannot occupy all the available vertical dimension of the screen. Thus, this type of apparatus would be unable to utilize the television screen's entire vertical resolution capability.
It will be appreciated from the foregoing that there is a definite need for a stereoscopic viewing apparatus and a related method for viewing on a conventional television screen two side-by-side related images, using the entire vertical resolution capability of the television screen, yet providing a three-dimensional image having the two-dimensional proportions of the conventional television image. It also will be appreciated that there is a need for a stereoscopic video recording that can be used with such an apparatus to provide that three-dimensional effect. The present invention fulfills these needs.